Telephone repeater



Jan. 15 1924.

O. B. JACOBS TELEPHONE REPEATIQJR Filed Oct. 18, 1919 ATTORNEY PatentedJan. 15, 1924.

'.UNITED STATES PATENT OFFICE.

OLIVER B. JACOBS, OI MO RBIS PLAINS, NEW JERSEY, ASSTGNOR '10 AMERICANTELE- P HONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

TELEPHONE REPEATEE.

Application filed October 18, 1919. Serial No. 881,878.

a To all whom it may concern:

Repeaters, of which the following is a spec1-- fication. v

My invention relates to repeaters, particularly to repeaters of the cordcircuit type.

It is an objectof the invention to provide for each telephone lineentering a repeater station, a separate balancing network and repeatertransformer designed to correspond to the impedance of the line and toplace the amplifying elements of the repeaters into the cord circuits,so that any one of the repeater cords may be used, to establishconnection between'any desired pair of lines. To permit of the making ofnon-repeater connections, I provide for each line a relay which isarranged to disconnect the repeater transformer and the net work fromthe line,

except when a repeater cord is associated with the line.

One form and arrangement of apparatus and circuits embodying theinvention is shown in diagrammatic view in the accompanying drawing inwhich reference character L designates a telephone transmission line,which is normally associated with switchboard conductors 1 and 2 bymeans of the back contacts 6 of a relay-3, a transformer 20 beingprovided to associate conductors 1 and 2 with the tip and ring contactsof a jack 4. A line is associated with a jack 4' by apparatus designatedby similar characters of reference, the prime mark bein used todistinguish the aparatus of line L' from that of line L. Both ines L andL are thus normally associated with the jacks 4 and 4' and an ordinarynonrepeater connection may be established between the two lines byconnecting the two jacks by an ordinary cord circuit.

For the purpose of connecting the two lines through a repeater there isrovided adjacent jack 4 of line L a jack 5, t e sleeve of which isconnected to the circuit of relay 3 so that this relay is energized whenground is connected to the sleeve, as described here- 7 inafter. Thewinding of one side of a repeater transformer 10 is connected to the tipand ring contacts of jack 5 and-the windings of the other side of thistransformer are connected by means of conductor 8 and 9 to the frontcontacts 6 of relay 3, the other terminals of these windings beingconnected to a network N, which has the same characteristic impedance asthe line L. The midpoints 16 and 17 of the transformer windings areassociated with contacts 12 of relay 3 these contacts being arrangedtoconnect' the said midpoints with the switchboard conductors 1 and 2when relay 3 is energized. For associating jacks 4 and 5 with thecorresponding jacks in line L there are provided repeater cord circuits21, comprising amplifying devices 14 and 15, and terminated by twinplugs 4, 5; and 4 5 en the operator desires to establish a repeaterconnection between lines L and L',

she merely associates the plugs of the repeater cord with the corresonding jacks.

As plug 5 is thus introduce into 1ts jack,

the sleeve of the jack is connected to ground so that relay 3 becomesenergized andconnects network N to the line, in place of jack 4. Thepoints 16 and 17 in the windings of transformer 10 are now points ofsymmetry between the line and the network the imedance of the linecircuit to the left thereof ein substantially equal "to the impedance oft e network circuit to their right. The front contacts 12 of relay 3connect the jack 4 with points 16 and 17, so that when current flows inline L a portion of the current is shunted from the line by means ofconductors 1 and 2, which current flows through transformer 20 over theti and ring contac s of jack 4 into the amp ifying device 14 in the cordcircuit, by means of which device 20', jack 4', amplifier 15, jack 5 andtrans- V former 10 into line L and network N.

For the purpose of sen'dinlg1 Morse and other signaling currents over te conductors of the telephone lines, there is associated with eachswitchboard conductor a c p sof cord circuit 21 with the v ite set 22 ofthe type well known in the art. Under ordinary circumstances the Morsecurrents flow over the back contacts 6 of relay 3 into the lineconductors. When repeater connections are established over the lines theMorse currents flow through the front contacts 12 of relay 3 to thepoints of symmetry 16 or 17, from which points half of the current flowsinto the network and half through front contacts 6 of relay 3 into theline. The Morse apparatus is thus associated with the line at the pointof symmetry between the line and its balancing network so that it causesno disturbance in the balance between the line and the network. Thecontacts 12 of relay 3 are arranged to close before back contacts 6 openso that there is no interruption of the continuity of the line. relativeto the Morse current. Other signaling apparatus may be associated withthe line in similar manner. The networks N are preferably grounded attheir midpoints so that the telegraphic current in one line circuit isunable to cause disturbances in the adjacent line circuit.

Although I have shown and described herein only one form and arrangementof apparatus embodying the invention, it is readily understood thatvarious modifications and changes may be made therein within the scopeof the following claims without departing from the spirit and scope ofthe invention.

What I claim'is:

1. In combination, atele hone line, a jack normally terminating sailine, an amplifying repeater comprisin a three-winding transformer, andmeans or at times interposing said transformer between said line andsaid jack.

2. In combination, a line, a jack normally terminating said line, anamplifying repeater comprising a three-winding transformer, a relay, andmeans for at times actuating said relay to inter ose said transformerbetween said line and said jack.

3. In combination, a line, a jack normall terminatingsaid line, anetwork for be ancing said line, a relay for at times disconnecting saidjack from said line and connecting thereto said network in balancingrelationship, and means operated by said relay for associating thepoints of symmetry between said line and said network with said jack.

4. Incombination, a line, a jack, a relay associating said jack withsaid line, a network for balancing said line, a repeater element, meansactuated by said relay for at times disconnecting sai jack from saidline and connecting thereto said repeater element and said network, andmeans actuated by said relay for connecting the midpoints of saidelement with said jack.

5. In combination, a pair. of telephone actuated when said cord circuitsare associated with said jacks for interposing one of the elements ofeach repeater between the line and one of its jacks.

6. In combination, a pair of telephone lines adapted to be connected forthrough service, a jack. for terminatin each line, a repeater elementfor each line, a relay for each line for inter-posing said elementbetween said line and its 180k, a second jack for each line, a secondrepeater element associated with each of said second jacks, a iair ofcord circuits for associating the gacks of said lines and means foractuating said relays when said circuits are associated with said jacks.

7. In combination, a pair of telephone lines, a first jack for eachline, a relay for each line for connecting the line with its jack, anetwork for each line for balancing the same, a second jack for eachline, a pair of cord circuits for associating the jacks of one line withthose of the other line, a repeater comprising amplifying devices, onein each of said cord circuits, and a pair of "input and output elements,means forassociating one of said elements with each of said second acks,means operated by sa1d relay for inter-posing the other of saidelements.

between said line and its first-mentioned jack and a circuit for saidrelay actuated when said cord circuits are associated with the saidjacks.

8. In combination, a line, a source of signaling current associated withsaid line, a switch to control said source, a network for balancing saidline, means for at times connecting said source and switch directly withsaid line and disconnecting said network and alternativemeans at'othertimes for associating said network with said line and connecting saidsource to a point of symmetry between the line and the network.

9. In combination, a plurality of telephone lines, jacks therefor,respective networks and repeater transformers associating said lineswith said jacks, and cord circuits'comprising amplifying devices forassociating said jacks.

10. In combination, two telephone lines normally adapted for directconnection, a two-way two-element repeater, and means to connect saidlines directly, or alternatively, through said repeater.

11. In combination, two telephone lines normally adapted for directconnection, respective balancing networks and three-windingtransformers, two repeater elements, and means to connect said linesdirectly, or al ternatively, to their networks through the transformerwindings and to connect the repeaters to the transformers.

12. In combination, two telephone lines normally adapted for directconnection or indirect connection, a two-way two-element repeater tobecomprised in the indirect connection, means to connect said linesindirectly through said repeater, a telegraph signal branch connecteddirectly to one side of one of said lines in their normal state, andmeans to connect it to a neutral point when the lines are connectedthrough the repeater.

13. In combination, two telephone lines normally ending in respectivejacks at the same station, telegraph signal branches con nected to eachside of each line, a repeater through which the lines may be connected,

and means to change the telegraph signal branch connections to neutralpoints when the lines are connected through the repeater.

14. In combination, two telephone lines normally ending in respectivejacks at the same station, a two-way repeater set comprising twothree-winding transformers, supplemental jacks each permanentlyconnected to a winding of the respective transformers, and twin plugs toconnect the repeatcr between the lines.

15. In combination, two telephone lines normally ending in respectivejacks at the same station, a two-way repeater set comprising twothree-winding transformers, supplemental jacks each connected to awinding of the respective transformers, twin plugs to connect therepeater between the lines, and relays controlled by the sleeves of theauxiliary jacks to connect. the transformers in operative relation whenthe twin plugs are inserted in the jacks.

16. In combination, a plurality of telephone lines, respectiveartificial lines and three-winding transformers associated with saidtelephone lines, two opposite-way amplifying elements, and means toconnect said elements for two-way two-element repeating between two ofthe said lines.

17. In combination, a plurality of telephone lines, respectiveartificial lines and three vinding transformers associated with saidtelephone lines, two opposite-way am plifying elements, means to connectsaid elements for two-way, two-element repeating between two of the saidlines, and alternative means to connect two lines directly withoutamplifying repeating between them.

In testimony whereof, I have signed my name to this specification this17th day of October, 1919.

OLIVER B. JACOBS.

